Pulse jet air cleaner systems; evacuation valve arrangements; air cleaner components; and, methods

ABSTRACT

Assemblies, features, and techniques for pulse jet air cleaner assemblies and their operation are described. Techniques described include methodology and equipment for preferred pulse jet sequencing and operation.

CROSS-RELATED REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. Ser. No. 14/940,377,filed Nov. 13, 2015. U.S. Ser. No. 14/940,377 is a continuation of U.S.Ser. No. 13/010,068, filed Jan. 20, 2011, which issued as U.S. Pat. No.9,186,612. U.S. Ser. No. 13/010,068 includes the disclosure of, withedits, U.S. provisional 61/297,522, filed Jan. 22, 2010 and U.S.provisional 61/324,493, filed Apr. 15, 2010. The complete disclosures ofU.S. Ser. No. 14/940,377; U.S. Ser. No. 13/010,068; U.S. Ser. No.61/297,522 and U.S. Ser. No. 61/324,493 are incorporated herein byreference. A claim of priority to each of U.S. Ser. No. 14/940,377; U.S.Ser. No. 13/010,068; U.S. Ser. No. 61/297,522 and U.S. Ser. No.61/324,493 is made to the extent appropriate.

FIELD OF THE DISCLOSURE

The present disclosure relates to air cleaner arrangements. Itparticularly concerns pulse jet air cleaner systems, in which a pulsejet cleaning flow is directed through a filter cartridge at selectedtimes.

Features, techniques, components and methods described relate, forexample, to: advantageous dust evacuation features; advantageous pulsejet control methodology; advantageous filter cartridge features; and,overall assembly configurations.

BACKGROUND OF THE INVENTION

The present disclosure relates to air cleaner arrangements used forexample, in vehicles and other equipment. It particularly concerns aircleaners with pulse jet systems, allowing for selected pulse jetcleaning of serviceable filter cartridges therein. This allows forextended service life of filter cartridges and operating life for thevehicle or other equipment before servicing as needed.

A variety of systems for pulse jet air cleaning are known. Examplesdescribed in U.S. Pat. Nos. 5,401,285; 5,575,826; 5,683,479, are pulsejet air cleaning systems for vehicles such as the M1 tank. Othersdescribed in U.S. Pat. Nos.: 6,676,721; 6,872,237; and 6,908,494, arepulse jet air cleaners for a media pack usable in heavy duty equipmentsuch as mining equipment or ore haulers. Each of the previouslyidentified six U.S. patents is incorporated herein by reference.

Further examples of pulse jet arrangements are described inPCT/US2007/014187, filed Jun. 18, 2007, and incorporated herein byreference in its entirety. The PCT application PCT/US2007/014187(published as WO 2007/149388, on Dec. 27, 2007, incorporated herein byreference) was filed with priority claims to each of three previouslyfiled U.S. provisional applications: U.S. provisonal application60/814,744, filed Jun. 19, 2006; U.S. provisional application60/848,320, filed Sep. 29, 2006; and U.S. provisional application60/921,173, filed Mar. 30, 2007. Each of these three provisionalapplications is also incorporated herein by reference.

Another example of pulse jet air cleaner systems is depicted in U.S.publication 2009/0308034 incorporated herein by reference. The systemdepicted in U.S. publication 2009/0308034 includes certain improvementsto arrangements of WO 2007/149388 in that a modified form of evacuatorvalve arrangement is provided.

In general terms, some pulse jet air cleaner arrangements such as thosedescribed in PCT/US2007/014187 have an evacuation valve assembly orarrangement thereon. The evacuation valve arrangement allows forevacuation of dust, water and/or air pressure from an interior of theair cleaner assembly, during a pulse jet cleaning operation. The presentapplication, in part, relates to improvements in such evacuation valvearrangements and their use.

The present disclosure also relates to improvements in air cleanersystems and components that may use pulse jet cleaning system and/orevacuation valve arrangements as characterized herein. Further, relatedmethods of assembly and use are described.

SUMMARY

According to an aspect to of the present disclosure, an air cleanerassembly is provided. The air cleaner assembly includes an air cleanerhousing; an air flow inlet; an air flow outlet; and, an interior. Thehousing includes an outer sidewall. A dust ejection port arrangement isprovided in the housing. The dust ejection port arrangement includes adust egress aperture arrangement in the outer sidewall on the housing. Adust receiver is positioned exteriorly of the housing and is oriented toreceive dust from the dust egress aperture arrangement.

A variety of examples and features are described. Also techniques ofoperation and use are described.

There is no specific requirement that an assembly or method include allof the features characterized above, or as defined herein, in order toobtain some benefit according to the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a pulse jet air cleanerassembly in accord with the present disclosure; in FIG. 1, selectedportions being shown broken away to show selected internal detail.

FIG. 2 is a schematic depiction of the assembly of FIG. 1, with an inletduct arrangement and outlet arrangement removed.

FIG. 3 is a schematic side elevational view of the componentry depictedin FIG. 2; in FIG. 3 a portion being broken away to shown internaldetail.

FIG. 4 is a schematic access cover end elevational view of thecomponentry depicted in FIGS. 2 and 3.

FIG. 4A is a schematic access cover end elevational view analogous toFIG. 4, but showing the assembly with an access cover removed.

FIG. 5 is a schematic access end elevational view analogous to FIGS. 4and 4A, but showing the assembly with both an access cover and aninternally received filter cartridge removed.

FIG. 6 is a schematic cross-sectional view of the housing componentrydepicted in FIG. 5, shown in a cross-section taken through a dustreceiver assembly thereof.

FIG. 7 is a schematic cross-sectional view of the assembly depicted inFIGS. 1 and 2.

FIG. 8 is a schematic outlet end elevational view of the componentrydepicted in FIG. 2.

FIG. 9 is a schematic view analogous to FIG. 8, depicting some exampledimensions.

FIG. 10 is a schematic perspective view of the assembly of FIG. 1, shownwith a view toward the access cover end and with certain inlet, outlet,and mounting features removed.

FIG. 11 is a schematic enlarged fragmentary view of a selected portionof FIG. 1.

FIG. 12 is a schematic view analogous to FIG. 6, but depicting anoptional variation.

FIG. 13 is a schematic side elevational view of a filter cartridgeusable in the air cleaner assembly of FIG. 1.

FIG. 14 is a schematic side elevational view of the filter cartridgedepicted in FIG. 12, with portions depicted broken away and shown incross-section to view selected detail.

FIG. 15 is a schematic top end perspective view of a first alternateassembly configuration according to the present disclosure.

FIG. 16 is an end elevational view of a second alternate assemblyconfiguration usable in accord with the present disclosure.

FIG. 17 is a schematic perspective view of a third alternate assemblyconfiguration in accord with the present disclosure.

FIG. 18 is a schematic perspective view of an alternate filter cartridgeusable in selected modified arrangements in accord with the presentdisclosure.

FIG. 19 is a schematic side elevational view of a filter cartridge ofFIG. 18.

DETAILED DESCRIPTION

I. Further Background Regarding Pulse Jet Air Cleaners Generally

-   A. General Features and Operation of a Pulse Jet Air Cleaner    Assembly

In general, pulse jet air cleaner assemblies comprise a housing havingan unfiltered air flow inlet and a filtered air flow outlet. The housingtypically has an access cover thereon, which is openable and/orremovable to allow service access to an interior assembly.

Operably positioned within an interior of the housing, is an air filtercartridge. This filter cartridge is typically configured as a service orserviceable component, and thus is removably mounted within the aircleaner housing. A typical filter cartridge comprises pleated mediasurrounding an open interior; the media typically extending betweenopposite end caps. The cartridge typically includes a seal arrangement,which removably seals to a selected portion of the air cleaner housing,when the cartridge is installed. Such a cartridge is described forexample in WO 2007/149388 in connection with FIG. 2 thereof; and, isdepicted having a seal (radial) thereon, which seals around an air flowoutlet tube. As an alternative, an end (axial) seal on the cartridge canbe used; see WO 2007/179388 at FIG. 22.

In a typical air cleaner, air to be filtered is brought into thehousing, through the air flow inlet. The air is then directed throughthe media of the filter cartridge, typically with an out-to-in flowpattern, with the filtered air reaching the open interior of thecartridge. The filtered air is then directed into an outlet tube, by(from) which it is removed from the housing.

In use, periodically the cartridge becomes occluded with dust or otherparticulate material collected thereon. In a pulse jet air cleaner, dustis periodically (i.e. when selected) pulsed off the cartridge and out ofthe housing. Typically, this is done by providing an arrangement fordirecting a pulse jet of air into the cartridge interior, against thedirection of outlet flow. This will, in part, pulse collected dustmaterial on the exterior of the cartridge off the cartridge andtypically out an evacuator arrangement provided for this purpose.Descriptions of such features are found in each of WO 2007/149388 and US2009/0308034, incorporated herein by reference.

It is noted that the source of pulse air can be a compressed air tank orcharge tank configured as part of the air cleaner or separately. Someexample features related to this are described in the examples of WO2007/149388 and US 2009/0308034. A variety of arrangements can be usedto control when the pulsing occurs. Some approaches to this aredescribed in WO 2007/149388 and US 2009/0308034, incorporated herein byreference.

In part the present disclosure concerns methods and features forevacuation of the dust from the housing. Example prior evacuatorarrangements are described in WO 2007/149388 and U.S. 2007/0308034.These arrangements can be advantageous in certain applications for use.However, modifications are desirable, in certain circumstances, asdiscussed herein below. The present disclosure, then, relates, in part,to provision of modifications to the evacuator valve arrangement to apulse jet air cleaner assembly.

-   B. Some Potential Issues with Prior Pulse Jet Air Cleaner    Arrangements

An issue in pulse jet air cleaner, is getting a good quality evacuationof dust from the interior of the housing outwardly.

In accord with the present disclosure, in general improvements andarrangements providing for dust egress from a pulse jet air cleaner areprovided. These improvements generally relate to providing forarrangements facilitating dust egress, which in part use, to advantage,swirling action of dust within the housing. These improvements canprovide advantageous dust ejection.

Also, in some applications it may not be practical to position an egressfor the dust from the housing through an evacuator valve arrangement atthe bottom of the air cleaner. For example, in some vehicles this maynot be a practical location due to other structure on the vehicle. Also,in some instances it may be desirable to have an evacuator egress fromthe housing be above the bottom of a air cleaner housing, for examplebecause is expected the air cleaner may be partly submerged, during awater fording operation, when dust ejection is desired. The presentdisclosure, in part, relates to methods and techniques for providingdust egress, from a dust evacuator valve arrangement, that can bepositioned at a location above a lower most portion of the air cleaner.

Advantageous features for an air cleaner assembly and components aredescribed, when the air cleaner assembly is to be used in a pulse jetmode in accord with the descriptions herein. Such features include:filter cartridge features; dust evacuator valve features; and, selectedhousing features.

Herein, some advantageous pulse control logic approaches, for achievingenhanced pulse cleaning effects are described. These can be applied in avariety of pulse jet air cleaning systems, to advantage.

II. An Example Pulse Jet Air Cleaner Assembly

The reference numeral 1, FIG. 1, indicates a pulse jet air cleanerassembly in accord with the present disclosure. Referring to FIG. 1, thepulse jet air cleaner assembly 1 comprises an air cleaner housing 2. Theair cleaner housing 2 is positioned secured by mounting band 5 tosupport bracket 6. The support bracket 6 can, for example, be a portionof a frame, or structure mounted on the frame, of equipment with whichthe air cleaner assembly 1 is to be used. Typically, the equipment is avehicle and the air cleaner assembly is used to filter intake air for aninternal combustion engine.

Still referring to FIG. 1, the air cleaner housing 2 generally comprisesa cartridge receiving chamber or portion 10, defined by a housingsidewall 10 a having an open end 11 over which is received an openableaccess cover 14. Typically, the access cover 14 is configured to beremovable, for service access to an interior 2 i of the air cleanerhousing 2.

Still referring to FIG. 1, the air cleaner assembly 1 is provided withan inlet arrangement 18 by which air to be filtered is directed into aninterior of the air cleaner housing 2. In the example depicted, an inletduct 18 x is shown at the inlet arrangement 18. The air cleaner assembly1 is also provided with an outlet arrangement 20 by which filtered airis removed from the air cleaner housing 2. In this example, the outletarrangement 20 comprises an outlet tube 21 positioned in an end 22 ofhousing 10 opposite open end 11. The outlet tube 21 is depictedpositioned with duct arrangement 25 secured thereto, by which filteredair can be directed, for example, to an engine air intake.

As indicated previously, air cleaner assembly 1 is a pulse jet aircleaner assembly, and includes componentry for selectively providing fora pulse jet of air thereto, in use. Referring to FIG. 1, at 30 isprovided a pulse jet assembly or system. The pulse jet assembly 30 forthe depicted arrangement includes a charge (or accumulator) tank 31 forcontainment of compressed gas, for example air, used for operating apulse jet system. The pulse jet assembly further includes appropriatevalve and flow direction arrangements, along with a control arrangementas selected, for directing a pulse of gas from charge tank 31 through aninternally received filter cartridge, as desired. Still referring toFIG. 1, for the example assembly 1 depicted, the pulse jet assembly 30includes: controller 32, electrical line 33 including line 34 forelectrical communication with a power source and any onboard equipmentsource necessary; valve assembly 35 including valve 35 a and solenoidunit 35 b. Nozzle 36 provides a fitting for a compressed air line. Apressure relief valve from tank 31 is indicated generally at 37. At 38,a restriction sensor is provided, for monitoring a pressure differentialbetween regions downstream of an internally received filter cartridgeand upstream (typically the atmosphere exterior of the housing). Thesecomponents can be used together, to provide for operation and control ofthe pulse jet assembly 30. More description relating to this is providedherein below.

The pulse jet air cleaner assembly 1, and the pulse jet assembly 30, caninclude many features generally in accord with the arrangements of WO2007/149388 and/or U.S. 2009/0308034, incorporated herein by reference.

Still referring to FIG. 1, the housing 2 includes a dust evacuatorarrangement 40 thereon; arrangement 40, FIG. 1, being depicted withportions broken away to view internal detail. The dust evacuatorarrangement 40 comprises a dust egress arrangement 41 in the sidewall 10a of the housing 2, by which air and dust can evaluate an interior 2 iof the housing 2. The evacuator valve arrangement 40 further includes adust receiver (or receiver housing) 42 positioned exteriorly of the aircleaner housing 2, to receive air and dust from dust egress arrangement41. The dust receiver 42 includes a dust outlet aperture or portarrangement 43 therein, positioned so that dust can be evacuatedexteriorly from the receiver or receiver housing 42. In the exampledepicted the aperture 43 is covered by an evacuator valve member 44.Alternatives are possible, as discussed below.

In FIG. 2, a drawing of selected portions of FIG. 1 is depicted. It isnoted that in FIG. 2, the assembly 1 is depicted with: the inlet duct 18x of inlet arrangement 18, FIG. 1, removed. In FIG. 2, inlet arrangement48 in sidewall 10 a can thus be seen. The inlet arrangement 48 is shownsurrounded by a mount 49 including mounts 18 a for the inlet duct 18 x.The mounts 18 a comprise posts 18 p and fasteners 18 f, in the exampledepicted. The mounting arrangement can, for example, comprise a threadedpost/nut arrangement, if desired. For the example depicted, fourmounting posts 18 p are provided, two being fully viewable in FIG. 2.(It is noted that a gasket can be positioned between mount 49 and inletduct 18 x (FIG. 1), if desired.

Also referring to FIG. 2, outlet duct 25 is shown removed from outlettube 21. Here, a mounting flange 20 f with mounting posts 20 p thereon,including fasteners 20 t, is shown, for use in securing duct 25 inposition. Again, a threaded post/nut arrangement can be used, asdepicted. A gasket 20 can be positioned flange 20 f, to facilitatesealing to duct 25, FIG. 1.

Still referring to FIG. 2, housing 2 (and thus assembly 1) can becharacterized as having a central longitudinal axis X passingtherethrough. The axis X is generally surrounded by the sidewall 10 a.Thus, in a typical assembly, the sidewall 10 a will be tubular with agenerally circular cross-section, although variations are possible.

Referring to FIGS. 1 and 2, it is noted that the particular housing 2depicted, is configured with a componentry positioned so that in generaluse, axis X will be positioned substantially horizontally. It is notedthat many of the features and techniques described herein can be appliedin a situation in which the housing is configured for central axis toextend generally vertically, in use. An example of such assembly isdescribed herein below, in connection with FIG. 15.

In FIG. 3, a side elevational view of the componentry depicted in FIG. 2is shown. Referring to FIG. 3, retainer 14 r for securing access cover14 in place is depicted. The example retainer 14 r shown is a wing nut,threadably mounted on a central yoke post 56, extending through aninterior of housing 2.

In FIG. 4, an end elevational view of the assembly 1 is provided. Theview is toward the access cover 14, and retainer 14 r and center post 56can be seen. Other features previously described are viewable.

In FIG. 4A an end view analogous to FIG. 4 is viewable, but with theaccess cover 14 (FIG. 4) is removed. A removable cartridge 50 isdepicted secured in place by retainer 104 which can be a wing nut. Also,an inlet valve/director member arrangement 60 discussed further below,is viewable.

In FIG. 5, an end view analogous to FIGS. 4 and 4A is depicted, with afilter cartridge 50 (FIG. 4A) removed as well as the access cover 14(FIG. 4). Here a mounting yoke arrangement 103, discussed below, forsupporting central mounting post 56 is depicted. Also depicted is acartridge support/guide rack arrangement 104 discussed further below.Further, a portion of pulse jet distribution arrangement discussed belowis viewable.

In FIG. 6, a cross-sectional view of the housing of FIG. 5 is depicted.In general, a cross-sectional view is taken through the assembly 1 at alocation also extending through the dust receiver arrangement 40, in aplane generally perpendicular to central axis X. Dust egress arrangement41, discussed in further detail below is viewable.

Attention is now directed to FIG. 7, a cross-sectional view of thecomponentry depicted in FIGS. 2 and 3, taken generally at a right angleto the view of FIG. 6. Referring to FIG. 7, the housing 2 is depictedoriented with the outlet 21 on the right and the access cover 14 on theleft, an orientation opposite to that shown in FIG. 3.

Referring to FIG. 7, within housing interior 2 i is positioned cartridge50. The cartridge 50 is a serviceable component. By this it is meantthat the cartridge 50 can be removed from the housing 2 for servicingand/or replacement. In general terms, the cartridge 50 comprises media51 extending between first and second end pieces or end caps 52, 53. Themedia 51 surrounds and defines an open filter interior 51 i. For theparticular example depicted, the media 51 is positioned between an outerliner 51 x and an inner liner 51 y, each of which also extends betweenthe end caps or end pieces 52, 53. The liners 51 x, 51 y would typicallybe sufficient porous, to allow gas flow through at least selectedportions thereof.

Positioned on end cap or end piece 52 is provided housing sealarrangement 100. The housing seal arrangement 100 is discussed ingreater detail below. In general, the housing seal arrangement 100provides that when cartridge 50 is installed, unfiltered air cannotbypass the media 51 to reach outlet 21.

Referring to FIG. 7, access cover 14 is secured in place by wing nut 14r on post 56. Post 56 is supported in place by yoke 103.

Also positioned on post 56 is a second fastener (wing nut) 104. Thesecond wing nut 104 biases against central portion 53 c of end piece 53,to secure cartridge 50 in place. Seal gasket 105 is shown positionedbetween wing nut 104 and end cap 53 c. Retainer 104 can be rotatablysecured on cartridge end cap 53, or can be a separate component.

In general terms, then, end cap 53 c includes a small central aperture53 o therein. The cartridge 50 can be slid over post 56 of yoke 103 withend cap 52 inserted first. Once post 56 projects through aperture 53 o,nut 104 can be positioned and tightened in place, to bias cartridge 50in the direction of arrow 106, to bias seal member 100 into a sealingorientation. Access cover 14 can then be positioned in place bytightening nut 14 over post 56.

Referring still to FIG. 7, attention is directed to guide member 105. Ingeneral, the guide member 105 provides a member toward which (and overwhich) the cartridge 50 is inserted. The guide member 105 helps theservice provider position the cartridge appropriately, as it is beingpushed in the housing 2. In general terms, the guide member 105comprises a cartridge support rack/guide. In the arrangement depicted,it is a loop mounted structurally within housing 1 at a location toextend toward end cap 53 of cartridge 50 when installed. Referring toFIG. 5, the support or rack 105 includes an end loop 1051 most remotefrom outlet 21, which dips downwardly somewhat, when mounted. Thecartridge 50, as the service provider inserts it into the housing 1,will extend over the support 105. Downwardly turned end 1051 will helpthe service provider get the cartridge positioned over the support 105,and riding therealong. Thus, bracket 105 will generally support thecartridge as it is pushed into position, facilitating alignment of thepost 56 through the aperture 53 o, and assisting the service provider inproperly aligning the cartridge 50 within the housing 2.

Other features viewable in FIG. 7 that relate to pulse jet air cleaningare discussed in further detail below.

In FIG. 8, an end elevational view taken toward the outlet end of thehousing 2 is provided. Thus, in FIG. 8, the view is generally towardoutlet tube 21. Selected features previously characterized are viewable.It is noted that in FIG. 9, an analogous view is provided, but with somedimensions discussed below indicated.

It is noted that in FIGS. 3, 4 and 9, some example dimensions, for anexample unit are depicted. These are intended to be examples only, withthe techniques being applicable in a wide variety of units. Theindicated dimensions are generally as follows: in FIG. 3, an assemblylength A indicated as =525.2 mm; an access cover diameter B beingindicated as 315.2 mm; a housing internal diameter C being indicated as300 mm; with other dimension indicated as follows: D=160 mm; E=80.1 mm;F=76.8 mm; G=341.1 mm; H=429.9 mm; I=95.2 mm; J=58.0 mm; and, K=43.9 mm.

In FIG. 4 some example dimensions and angles are indicated as follows:dimension L=220.1 mm; dimension M=150.9 mm; dimension N=245.5 mm; angleO=75°; angle P=65°; and, angle Q being 3°. In FIG. 9, example dimensionsare as follows: dimension R=86.3 mm; dimension S=48.5 mm; dimensionT=50.3 mm; dimension U=21.1 mm; dimension V=73.2 mm; and, dimensionW=21.4 mm

Attention is now directed to FIG. 10. In FIG. 10 is provided a schematicdepiction of the pulse jet air cleaner assembly 1, modified from FIG. 1in that the inlet arrangement 18 is removed; and, the view is toward theaccess cover end.

Referring to FIG. 10, at 48 an inlet aperture arrangement is depicted(as part of inlet arrangement 18) in (i.e. through) the housing sidewall10 a. For the particular example depicted, the inlet aperturearrangement 48 generally defines an arcuate, rectangular, perimeter 48p, although alternatives are possible. At 18 p the mounting posts aredepicted. The inlet aperture arrangement 48 depicted is a singleaperture, although alternatives are possible.

Still referring to FIG. 10, air cleaner assembly 1 includes, positionedin interior 2 i, in extension over inlet aperture arrangement 48, aninlet valve/director arrangement 60. For the example depicted, the inletvalve/director arrangement 60 comprises a flap 61 hingedly secured alongedge 62 by fastener arrangement 63 to an interior 10 i of sidewall 10 a.Thus, the flap 61 can deflect inwardly from the housing sidewall 10 a,or can be pressed radially outwardly against the sidewall 10 a dependingin the flow/pressure condition within interior 2 i.

In general terms, the valve/director arrangement 60 can be characterizedas having first and second orientations or positions. In the firstorientation or position, the inlet valve/director arrangement is open,i.e. flap 60 is biased away from sidewall 10 i, allowing air to enterinterior 2 i through aperture arrangement 48. In the second position ororientation, the valve/director arrangement 60 is oriented closed, i.e.with flap 61 biased against sidewall 10 i closing aperture 48.

Attention is now directed back to FIG. 4A. In FIG. 4A flap 60 is shownbiased away from sidewall 10 i, at least partially. This allows air toenter aperture arrangement 48, FIG. 10. It is understood that the flap60 may deflect further away from wall 10 i, FIG. 4A in actual use. Thiswould be indicated by arrow 64. On the other hand, arrow 65 suggests howthe flap 60 would move under internal pressure, to close aperture 48.Support 66 is provided, underneath flap 60, to inhibit inversion of theflap 60, and also to help hold the flap 60 up and out of the way duringservicing of cartridge 50.

The inlet valve/director 60, i.e. flap 61, can be (in general) in accordwith arrangements described in WO 2007/149388 and U.S. 2009/0308034, andincorporated herein by reference.

In general terms, the inlet arrangement 18, in combination with theinlet valve/director 60, when generally as depicted herein, can becharacterized as a tangential inlet flow arrangement or assembly. By theterm “tangential” in this context, it is meant that air flow intointerior 2 i is generally not directed (specifically and directly)toward a central axis X, FIG. 2, of the housing sidewall 10 a andcartridge 50, but rather is directed into a circular (cyclonic) patternaround the outside of the cartridge 50, in part against interior surface10 i of sidewall 10 a. This tangential direction is facilitated by theinlet valve/director 60, because as air enters through inlet 18, FIG. 1,the flap 61, FIG. 4A, will deflect downwardly toward the cartridge 50.This will cause air flow into interior 2 i to adopt a spiral pattern, inthis instance, counter clockwise when viewed toward end 11 of housing 2;i.e. from the orientation of FIG. 4A although an opposite flow directionis possible.

In general terms, then, the tangential inlet flow arrangement isconfigured to direct air flow passing into an interior 2 i of thehousing 2, into annulus 10 x surrounding the cartridge 50 interiorly ofsidewall 10 a, in a pattern that is generally circular around centralaxis X, FIG. 2, rather than being directed toward central axis X, FIG.2.

Herein, in general terms, the air cleaner housing or (assembly) willsometimes be characterized as having or defining a cyclonic or spiralingdust direction, or a dust rotation direction. This is meant to indicatethe general direction of spiral movement of the dust entering thehousing, around the cartridge 50. The particular housing depicted, FIG.5, is configured with a counter-clockwise direction, when viewed in theorientation of FIG. 5. Of course, the componentry can be configured foran opposite clockwise direction if desired.

It is noted that cyclonic or spiraling dust direction (i.e. dustrotation direction) can be provided by other structure within theassembly 1. An example described below involves a fin arrangementpositioned on the cartridge. As described below, when alternatearrangements provided for causing dust spiraling or rotation, it may bethat the inlet does not need to be a tangential arrangement.

It is noted that when the pulse jet assembly 30 is operated, the inletvalve/director 60, i.e. flap 61, under pressure provided interiorly ofhousing 2 by the pulse jet, will deflect back, closing aperturearrangement 48 briefly. This will help inhibit ejection of dust frominterior 2 i out inlet aperture arrangement 48. In addition, as the flap61 closes aperture arrangements 48, pressure in interior 2 i of housing2 will build, facilitating a push of dust, from the pulse, out ofinterior 2 i and into dust receiver 42.

More specifically, when the pulse jet air cleaner assembly 30 isoperated to pulse a cleaning jet of air through cartridge 50, and theinlet valve/director 60 is closed, the dust is generally directedexteriorly of the housing 2, via dust egress arrangement 41, and intodust receiver 42.

The dust egress arrangement 41, FIGS. 6 in some application ofprinciples of the present disclosure, is provided with no portionthereof in radial overlap with a lowermost portion 10 b of the housing 2and sidewall 10 a; i.e. with no portion thereof directed straightdownwardly. In such instances, typically, the lowermost portion 41 b(FIG. 6) of the dust egress arrangement 41, FIG. 1 is positionedradially offset from a lowermost portion 10 b of the housing sidewall 10a, FIG. 6, around axis X, FIG. 2, by at least 30°, typically at least45°; and usually at least 75°. Indeed, in some applications, thelowermost portion of the dust egress arrangement 41 is positioned atleast 90° rotationally around the housing sidewall 10 a (and axis X)from a lowermost portion 10 b, so that the entire aperture 41 ispositioned in the upper half of the housing, when the housing ispositioned with central axis X thereof directed generally horizontally,and with lower port 10 b directed downwardly. This is as depicted forthe assembly of FIGS. 1-6.

Often, no portion of dust egress arrangement 41 is in a portion of thehousing directed straight up.

The dust egress arrangement 41 can comprise a single aperture (asdepicted in FIG. 1) or plurality of apertures. It can be provided withframework extending thereover, if desired. When the dust egress aperturearrangement 41 comprises a plurality of apertures, when reference ismade herein to a lowermost portion, reference is meant to the radiallylowermost portion of the lowermost aperture, around central axis X.

Referring to FIG. 6, a typical egress arrangement 41 can be seen. Thetypical aperture 41 extends, in housing sidewall 10 a, over a radial arc(arc from edge 41 c to edge 41 b, FIG. 6) around central axis X, FIG. 2,of at least 20°, typically at least 30°, usually at least 45° and oftenwithin the range of 45°-90°.

When the dust egress arrangement 41 comprises a plurality of apertures,reference to the arcuate extension is meant to radially most spacedapart edges. For the example assembly depicted, in FIG. 6, this would bebetween opposite edges 41 b, 41 c and would correspond to an arcuateextension between a radially lowermost edge 41 b and a radiallyuppermost edge 41 c.

It is noted that with the assembly as depicted in WO 2007/149388,typically the evacuator aperture in the housing sidewall is directeddownwardly in use, and does not extend over as wide an arc. Thearrangement of FIG. 1 also differs substantially from the arrangementsof U.S. 2009/0308034. There, although in some instances apertures in theupper half of the housing are depicted, in no example depicted thereinare the apertures exclusively positioned and/or sized as described aspreferred above, and also depicted oriented to direct dust into a dustreceiver arrangement or housing as described.

It is also noted that typically, with the housing 1 positioned with acentral axis extending horizontally, FIG. 6, the dust egress arrangement41 is often positioned with no portion thereof in radial extensionacross an upper most portion 10 u of the housing 2 and sidewall 10 a,FIG. 6. Indeed, typically, the uppermost portion 41 u of the dust egressarrangement 41, FIG. 1, is positioned radially offset from an uppermostportion of 10 u of the housing sidewall 10 a, around axis x by at least3°, typically at least 5° and usually at a location within the range of3°-25°, although alternatives are possible.

Referring to FIG. 11, an enlarged of FIG. 1, the dust evacuatorarrangement 40 includes a receiver housing 42 positioned to receive dustfrom interior 2 i, as the dust passes outwardly from housing interior 2i through sidewall 10 a, i.e. through dust egress arrangement 41.Referring to FIG. 11, the example receiver housing 42 depicted comprisesa top wall section 42 t, a bottom wall section 42 b, and an end 42 c.The end 42 c is remote from sidewall 10 a and is depicted with a portarrangement 43 therethrough, for dust ejection from dust receiver orhousing 42.

Still referring to FIG. 11, the receiver housing 42 can also becharacterized as having opposite sidewall sections 42 u, 42 v, eachextending between the top section 42 t and the bottom section 42 b.

In more general terms, and referring to FIG. 11, the receiver housing 42can be characterized as having first and second, opposite, sidewallsections 42 x, 42 y. Referring to FIG. 6, when the receiver housing 42is positioned on an air cleaner housing 2 in which the central axis Xextends generally horizontally, the first housing section 42 x can becharacterized as a top or upper section 42 t, and the second, opposite,sidewall section 42 y can be characterized as a bottom section 42 b.Thetwo sections 42 a, 42 b generally extend parallel to one another orsubstantially parallel to one another, however this is not required inall applications of techniques described herein. In general the term“substantially parallel” when used in this context, is meant to refer tosection 42 x, 42 y either extending parallel to one another or extendingin planes within +/−10°, inclusive.

Also, typically at least one of the sections 42 x, 42 y can becharacterized as a generally “tangential” section, with respect to thehousing outer sidewall 10. By this, it is meant that the referencedsection generally extends in a direction away from housing sidewall 10in a direction substantially tangentially to a circle defined by theouter sidewall 10. By “substantially tangentially” in this context inthis context, it is not meant that the section is necessary preciselytangential to such a circle, but rather that it is generally tangentialto such a circle, for example in a plane extending at +/−10°, inclusive,of a tangent to such a circle. Of course, for the assembly depicted inFIG. 6, top sidewall section 42 t extends generally tangentially to acircle which is defined by the outer sidewall 10 o. It is noted that thebottom wall 42 b depicted extends generally tangentially to a circlethat is somewhat smaller than the housing sidewall 10 a, but which isstill centered on axis X.

Referring to FIG. 1, it is noted that sidewall section 42 x, 42 y aregenerally positioned spaced apart with opposite sidewall sections 42 d,42 e extending therebetween. Referring to FIG. 6, for the particulardust evacuator arrangement 40 depicted, inner lip or flange 67 isprovided, directed upwardly from the lowermost portion 42 b of thehousing 40, at egress arrangement 41; the flange 67 ensuring that thebottom 42 b is positioned below a lowermost portion 41 b of egressarrangement 41. Typically, flange 67 will project upwardly at least 0.5inch (12.7 mm) above bottom 41 b, usually at least 0.6 inch (15.2 mm),and often 0.7-1.25 inch (17.8-31.8 mm), although alternatives arepossible. The flange 67 helps inhibit dust in receiver 42 fromreentering interior 2 i. (Alternately stated, bottom 41 b is typicallyat least 0.5 inch (12.7 mm) below egress 41, usually at least 0.6 inch(15.2 mm) below, often 0.7-1.25 inch (17.8-31.8 mm) below).

From a comparison of FIGS. 1, 2, 4A, 5 and 6 general operation assembly1 with respect to dust egress will be understood. When the air entersthe housing in a cyclonic pattern as described, and swirls around theoutside of the cartridge 50, a portion of the dust contained with airwill swirl (rotate) around annulus 10 x, FIG. 4A, between the cartridge50 and interior surface 10 i of sidewall 10 a. Under this cyclonicmovement, a portion of the dust will, in due course, be ejected throughegress arrangement 41, FIG. 6, into dust receiver 42.

When the pulse jet is operated, dust is blown off the cartridge 50 (bythe pulse jet) and into annulus 10 x, (and valve/director 60 will closeas a result of the pressure). The pulse will force dust from interior 2i, outwardly through egress arrangement 41. Referring to FIG. 4A, it isnoted that during pulse jet operation, flap 60 will bias in thedirection of arrow 65 against sidewall 10 a. This will inhibit dust frombeing ejected out inlet aperture 48 and will also help provide anincreased pressure within housing interior 10 i to facilitate dustejection out dust egress aperture arrangement 41.

In the example assembly 1 depicted, FIG. 11, aperture 43 of dustreceiver 42, is covered by a flap valve arrangement 75. The examplevalve arrangement 75 depicted comprises a valve member 76 secured alongedge 77 by fastener arrangement 78. When the pulse jet occurs, valvemember 76 will be biased away from aperture 43, allowing dust ejectionfrom housing 40. When the pulse jet is not operated, typically areceiver interior pressure due to air flow through assembly 1, will helppull valve member closed 76 over aperture 43. Typically, the edge 77along which fastening occurs is a top or upper edge, althoughalternatives are possible. (Multiple flaps can be used as flap valvearrangement 75).

It is noted that in some systems, it may be desirable to attach dustejector port aperture 43 to a scavenger system, rather than rely on avalve arrangement.

In FIG. 12, a view generally analogous to FIG. 6 is provided, with aoptional variation shown. In particular, a radially inwardly directeddust collection flange or scoop arrangement 85 is provided, directedradially inwardly from the of dust egress arrangement 41. Edge 85generally corresponds to the most downstream edge of the dust egressarrangement 41 in a direction corresponding to dust cyclonic radialdirection. The radial inward projection or scoop 85, away from interior10 i of sidewall 10 a, will facilitate swirling dust collection in thedirection of arrow 86 being moved out from interior 10 i and intoreceiver 42. Typically, the most upstream edge or end of flange or scoop85, indicated generally at 85 c will extend radially inwardly at least0.25 inch (6.4 mm) typically at least 0.5 inch (12.7 mm) from a locationcorresponding to general curve of the sidewall 10 i. It is noted thatedge 85 will typically be bent inwardly, but remain contiguous with thewall, rather than being cut and bent inwardly, although alternatives arepossible.

III. The Filter Cartridge, FIGS. 13 and 14

Attention is directed to FIG. 14, in which an example cartridge 50 isdepicted. In FIG. 15, the cartridge 50 is depicted with a portion shownin cross-section.

As previously discussed, in connection with FIG. 7, the cartridge 50comprises a media pack 51 extending around open interior 51 i. The mediapack 51 is positioned between outer liner 51 x and inner liner 51 y. Forthe particular cartridge 50 depicted, the media pack 51 comprisespleated media having alternating inner pleat tips 95 and outer pleattips 96, FIG. 14.

A variety of media can be used for the media pack 51. The choice ofmedia will be selected based on such concerns as cost; desiredefficiency; desired lifetime of use; etc. Cellulose media can be used,as can synthetic media.

It is noted that, in general, a pulse jet cleaning arrangement asdescribed herein, will often be used on equipment subject to high dustload environments, and high flow rate circumstances, i.e. a relativelyhigh or high velocity flow of air and dust through the air cleaner inuse. In instances where it is expected that the media pack may besubject to substantial air flow rates and dust flow, it may be desirableto provide enhanced media pack features protection of the media packs,from dust damage. One manner, in which the media pack can be protectedagainst deterioration, would be to provide the media pack of syntheticmedia such as polyester media. Also, or alternatively, it may bedesirable to protect the outer pleat tips 96 against abrasion from dustmoving thereacross, as the air cleaner is operated. This can be done forexample by coating the outer pleat tip 96 with a protective material,such as an acrylic. This can be a useful application whether the mediais synthetic or cellulose.

In general, a non-flammable water based acrylic capable of either beingair dried or heat cured can be used. The material will provide forabrasion and corrosion resistance to the media. The media pleats (whichare form the outside pleat in the cartridge) can be coated by dipping orbrushing with a tip coating of approximately ⅛ inch (3.2 mm) in depth(i.e. height).

It can also be desirable to provide protection to the media pack, in theform of a barrier applied around the media pack 51, at one or moreselected locations. An example of this is shown in FIG. 13. Inparticular, and referring to FIG. 12, the outer liner 51 x depicted,includes imperforate barrier or margin 97 adjacent end cap or end piece52 and a second imperforate barrier or margin 98 positioned againstadjacent end cap 53. The margins or barriers 97, 98 are regions wherethe outer liner 51 x is imperforate. Each extends over a distance of1.0-4.0 inches (25.4-102 mm) axially along the outside of the end cap.Region 98 would, for example, be overlapped where air entered throughinlet 48 r of the air cleaner; and, region 97 would overlap, forexample, where air exits through the dust egress arrangement 41. Bothare regions where substantial dust contact with the media wouldotherwise occur, which can damage the media.

For the particular example arrangement depicted, FIG. 13, region 97 isgenerally axially longer than region 98, typically at least 0.75 inch(19 mm) longer and usually at least 1.25 inch (31.8 mm) longer.

For the example depicted, dimension AA is 3.0 inch (76.2 mm) anddimension BB is 1.5 inch (38.1 mm) although alternatives are possible.

Still referring to FIG. 13, the particular cartridge depicted isprovided with a margin 97, 98, by providing the outer liner 51 x on theform of a perforate metal cylinder, with perforations 99 therethrough,at appropriate locations, leaving the margins 97, 98. Alternatively, anexpanded metal liner can be used, with shields positioned adjacent oneor more of the end pieces 52, 53.

Referring to FIG. 14, it is noted that the inner liner 51 y is depictedas an expanded metal liner, although alternatives are possible.

Referring to FIG. 7 cartridge 50 is depicted with adhesive coils orbeads 51 a, 51 b extending around an exterior and interior of the media51. These can provide for media integrity and pleat spacing. Such beadsare not shown in the depictions of FIGS. 13 and 14, but can be includedwith features thereof.

It is noted that to facilitate dust cleaning, the media can be providedwith a fine fiber thereon, such as described in U.S. Pat. No. 7,270,693and U.S. Pat. No. 6,994,742, incorporated herein by reference. Suchmedia helps ensure good surface loading and high efficiency, and alsofacilitates cleaning the dust off the cartridge during pulsing.

In FIG. 14, attention is directed to housing seal arrangement 100. Thehousing seal arrangement 100 generally comprises an axial seal member101, positioned to provide seal under pressure directed in the generaldirection of axis X. Such sealing can be understood for example byreferring to FIG. 7, in which the seal member is shown biased againstportion of housing 2 (in this instance a portion of tank 31) by bolt orfastener 104. Referring again to FIG. 14, the housing seal arrangement100 depicted, includes an axial seal ring 101 and a flexible lip orflange 102. Such a seal, for example, can be preformed and then besecured to end piece 52. A typical seal material would comprise, forexample: Neoprene; EPDM rubber; Neoprene-EPDM; urethane, or a variety ofalternative commercially available seal materials.

IV. Some Selected Alternatives, FIGS. 15-19

It is noted that the principles described herein can be configured in avariety of alternative configurations. Examples of some possiblealternative configurations will be understood by reference to FIGS.15-19.

-   A. An Assembly Configured for Vertical Orientation, FIG. 15

Attention is first directed to FIG. 15, in which assembly 200 isdepicted. The assembly 200 comprises a housing 201 having a sidewall 210with a central axis X extending generally vertically. Access cover 214,secured in place by nut 215, can be seen. In general housing 210includes inlet arrangement 220 positioned at an end of sidewall 210adjacent access cover 214 and sized and configured generally analogouslyto inlet arrangement 18, FIGS. 1 and 2.

At 240 a dust receiver is depicted, comprising first and second,opposite, sidewall sections 241, 242, each extending generallyanalogously to sections 42 t, 42 b (FIG. 11) but positioned as sidewallsections, rather than as top and bottom wall sections. The opposite topand bottom wall sections are indicated generally at 243, 244,respectively. Valve arrangement 246 for dust ejection, generallycomprising a flap valve 247 secured along edge 248 by retainerarrangement 249, is depicted. In this example, securement is again alongan uppermost edge, but in this instance, the edge extends between thetangential sections 241, 242 rather than along one of them.

Other features of the assembly 200 may be generally as previouslydescribed except now oriented in the vertical orientation shown. Thus,in housing sidewall 210, covered by dust receiver 240, is positioned anaperture arrangement (dust egress arrangement) analogous to dust egressarrangement 41, except oriented in a radial arc around central axis Xwhich is extending vertically than horizontally. The optional scoop ordirection arrangement 85 described above can be used for the assembly inFIG. 14, as can other features and configurations described.

-   B. Alternate Dust Egress Direction, FIG. 16.

Attention is now directed to FIG. 16, a view generally analogous to FIG.5, except shown with different dust egress direction, and thus dustegress aperture arrangement location and dust receiver direction. InFIG. 16, assembly 300 comprises a housing 301 with a sidewall 310. Adust receiver housing is indicated generally at 340 having oppositesidewall sections 341, 342, of which section 341 generally tangential tothe sidewall 310, and each of which is directed downwardly. Thus, a dustegress direction from within housing 301, indicated generally by arrow350, would extend through a dust egress aperture arrangement locatedgenerally where indicator 351 is provided. It could otherwise beanalogous to aperture arrangement 41, FIG. 6, and could use the optionaldirector or scoop arrangement indicated generally at 85, FIG. 12. Otherfeatures for the housing 301 can as generally described in connectionwith FIGS. 1-14 and are numbered accordingly.

-   C. A Dust Shield positioned within the Housing, FIG. 17

It is noted that protection of an interiorly received filter cartridgefrom accelerated deterioration due to dust impact, can be managed in avariety of ways. In FIG. 17, an optional feature to facilitate this isdemonstrated. Referring to FIG. 17, assembly 400 is depicted comprisinghousing 402 including sidewall 410 and access cover 411. The assembly400 can include features as previously described, for example inconnection with any of FIGS. 1-16, if desired. The example depicted,includes many features analogous to the assembly 1 of FIGS. 1-14.

In FIG. 17, assembly 400 is shown with a portion of sidewall 410 tbroken away to shown internal detail. At 420, an internal shield isdepicted. The shield 420 which can be secured within the housing aroundall of, of a portion of, an internally received cartridge, is shownadjacent to, and an overlapping orientation with, a dust egress aperturearrangement indicated generally at 421 and which can be generallyanalogous to dust egress aperture arrangement 41, previously discussed.The shield 420 can extend partially around an internally receivedcartridge or entirely around a received cartridge. The particular shield420 depicted will help protect the cartridge from dust moving throughegress aperture arrangement 421.

It is noted that the shield 420 of assembly 400 can be used incooperation with a vertically oriented unit if desired, further it canbe used in association with various ones of the features and optionsdiscussed herein.

It is noted that when a dust shield as part of a housing is used incoordination with the assembly in accord with principles describedherein, it may be useful and/or desirable to provide a cartridge thatdoes not have margin (i.e. protective shield portion) thereon adjacentthe end cap having a housing seal arrangement thereon. Thus, for examplea margin indicated at 97, FIG. 13, can be avoided.

-   D. An Example Dust Director, FIGS. 18-19

Herein above, a description of a technique used to induce cyclonicmovement of air and dust around the cartridge 51 was described. Theparticular technique described involved providing generally tangentialinlet air flow as a result of combination of inlet valve/director 60,FIG. 4A; and, the direction of the inlet arrangement 18 and inlet duct18 x, FIG. 1. Alternate or additional features and techniques can beused. An example is provided in connection with FIGS. 18 and 19.

Referring to FIG. 18, cartridge 500 is depicted comprising a media pack501 extending between opposite end caps 502, 503. End cap 502 can begenerally analogous to open end cap 52, FIG. 13, and have an analogousseal member thereon. End cap 503 can be analogous to end cap 53, FIG.13. In the example cartridge 500 depicted, fastener 507, which operatesanalogously to fastener 104, is provided rotatably, loosely, secured tothe end cap 503.

Adjacent end cap 503 is provided an air flow director arrangement 510comprising a mount 511 having a plurality of air flow director vanes 512thereon.

The air flow director arrangement 510 is positioned around a portion ofthe cartridge 500 that is positioned (or potentially positioned,depending on rotational alignment) overlapped by an inlet arrangementfor gas flow into the housing, in use. As the air is drawn into thehousing, it will pass through the director arrangement 510 and will bedirected by the vane 512 into a circular or cyclonic pattern around thecartridge 500. For the particular cartridge 500 depicted in FIG. 18,this would be a clockwise flow, when viewed in the direction of end cap503. Of course, an opposite counter-clockwise flow can be induced, byusing alternately directed vanes 512. A cartridge analogous to cartridge500 can be used in an air cleaner assembly having features generallyanalogous to those previously described herein. Of course, if cartridge500 was used in some of the previous assemblies as specificallydepicted, it would need to be modified for “counter-clockwise flow” whenviewed in the direction of end cap 503, to facilitate a proper dustrotation direction within the housing, for the particular dust egressaperture arrangements depicted.

Referring to FIG. 19, a side elevational view of cartridge 500 isdepicted.

V. Pulse Jet Features; Compressor Size Issues; Pulse Jet Operation(Control) Logic

-   A. Pulse Jet System Features

As previously discussed, air cleaner assemblies according to the presentdisclosure generally are pulse jet air cleaner assemblies; i.e. theyinclude equipment configured for directing a pulse jet of air, as apulse jet or cleaning flow, through a filter cartridge received therein,generally in a direction opposite normal filtering flow. Some general,adaptable, features relating to pulse jet air cleaner operation, aredescribed in selected ones of the references discussed previously. Inthis section, a general characterization of some usable selected pulsejet features is provided.

Attention is first directed to FIG. 7. In general, air cleanerassemblies in accord with the present techniques, will include a pulsejet distribution arrangement 600 therein. The pulse jet distributionarrangement 600 will typically at least include a pulse jet flow tube601 configured to direct a pulse flow of gas through an interiorthereof, from a region exterior of the cartridge 50, into the openfilter interior 51 i of the cartridge 50. The tube 601 may terminateshort of entering the cartridge 50, or it may extend into the cartridge50, depending on the system.

Still referring to FIG. 7, the particular pulse jet distributionarrangement 600 depicted includes, positioned against an exit end 610 oftube 601, a pulse distributor member 605. The example pulse distributormember 605 is a conical splitter oriented spaced from, and in overlapwith, end 601. As gases of a pulse impact peak 605 p, of distributor605, they will generally be directed radially outwardly, in a somewhatconical pattern. The splitter 605 is shown mounted to tube 601, bysupport 606. A conical spreading of the pulse by splitter 605 canfacilitate cleaning of the cartridge 50, along its axial length.

Still referring to FIG. 7, the assembly 1 depicted includes an outlettube 621 which extends into the cartridge interior 51 i, through centralair flow aperture 52 o in end cap 52. The outlet tube 621 ends at anoutwardly flared end 621 f, at the end most toward end cap 53. The tube621 facilitates desirable pulse distribution within cartridge 51,especially to help ensure that portions of the cartridge 50 mostadjacent end cap 53 are adequately pulsed or cleaned.

In general terms, outlet tube 621 is an exit tube for filtered air, fromcartridge 50 to be directed to outlet 21. Typically, tube 621 isnon-porous and generally circular in configuration, althoughalternatives are possible.

An outlet tube analogous to tube 621 is discussed at length in WO2007/149388, previously incorporated herein by reference.

Typically, an interior diameter of end 610 of tube 601 (or largestcross-sectional dimension, if not circular) is no more than 40%,typically no more than 35%, and usually 15-30% of an internal diameter(largest cross-section if not circular) of tube 621 in regionsurrounding the outlet 610.

Further, typically the tube 621 projects into cartridge 50, throughaperture 52 o, a distance extending at least 35%, usually at least 40%and typically 40-60%, inclusive, of an axial length of the cartridge 50between end caps 52, 53, although alternatives are possible.

Typically, the open end 610 of the tube 601 has a cross-sectional areaof no more than about 16% of a cross-sectional area defined by andimmediately surrounding portion of tube 621. Typically the open area oftube 610 is no more than 12%, and usually within the range of 2-9%, ofthe open area of a portion of tube 621 surrounding it.

Typically, an exterior diameter of the outlet 621, (discounting flare621 f) is no more than 80%, of an internal diameter of cartridge openarea 51 i. typically the outer diameter of tube 621 is at least 65% ofthe diameter of interior region 51 y (when the tube 621 and/or theinteriors 51 i are not circular, typically the reference is meant tolargest cross-sectional dimension).

Still referring to FIG. 7, it is noted that the conical distributor 605defines, around peak 605 p, a conical angle. Typically, that angle is atleast 40°, and usually not more than 80°, typically 50°-70°. An examplearrangement is depicted in FIG. 7, has a conical angle of about 60°.

Still referring to FIG. 7, at 8 a conical angle between ends 610 of tube601 and end 621 e of tube 61 (discounting flare 621 f) is defined.Typically angle H is no more than 30°, often no more than 27°, andsometimes not more than 25°. In a typical example, although alternativesare possible, angle H will be at least 20°, typically at least 22°.

Referring again to FIG. 7, the particular assembly 1 depicted, includesan accumulator tank or compressed gas tank 31 positioned secured tohousing 2, at an end 2 e of the housing 2. In the example depicted, tank31, is in part, surrounded by sidewall 10. The tank 31, for the exampledepicted, has a donut or tube shape, and is positioned around an openinterior 31 x, which serves as a portion of an outlet aperture forfiltered gas flow from housing 2. The tube 601 brings a pulse from valvearrangement 35 through tank 31 into aperture 31 x and then around bend601 b, toward interior 51 i. Thus, the valve arrangement 35 provides fora pulsing of gas contained within tank 31 through 601 into cartridgeinterior 51 i.

It is noted that many techniques as described herein can be applied insystems which do not have a compressed gas tank (accumulator tank)analogous to tank 31 positioned in (i.e. secured to) the housing 2, forexample at an end of the housing sidewall 10. For example, tank 31 canbe alternately located, or the air cleaner assembly 1 can be providedwithout such a tank, but with equipment that can be attached to ducting(tubing) from a remote tank (such as a tank on a vehicle or otherequipment with which the assembly would be used) that serves a anadditional purpose.

Referring now to FIG. 8, a view taken through aperture 21 and aperture31 x, a portion of tube 601 adjacent bend 601 b can be seen.

Referring back to FIG. 1, controller 32 includes appropriate processormemory capabilities, (control card) that are programmed in accord withthe preferred pulse control logic, for example as described herein toprovide for a monitoring of restriction condition (R_(c)) as described(tank pressure if needed) and initiation of the pulse valve assembly 35as described. A control unit 32 including such features can beimplemented with hardware and/or software components, in accord withconventional, commercially available, technology. Such equipment andprogramming features are within the skill of one of skill in the art ofmicroprocessor provision and programming.

-   B. Compressor Size/Type

For a typical pulse jet cleaner system in accord with the principlesdescribed herein, compressed gas pressure used in a pulse is typically100 psi (6.89 Bars), and each pulse generally requires one cubic foot(0.028 cu. meter) of air. Herein, in this context, the reference to “onecubic foot of air” is meant to approximate a cubic foot of air instandard condition (which would then be compressed in a tank to asmaller volume).

In general, pulse jet cleaning systems can be provided in two overallforms. In a first, a relatively small compressor system is provided onthe vehicle or other equipment generally dedicated to the pulse jetsystem involved. When this is the case, the compressor will typically berelatively small, typically under 1 horsepower (hp), an example being a¼ horsepower (hp) compressor with an output of 1 cu. ft./min at 100 psi.Such systems may take a significant period of time, for example about to50-90 sec. to charge a compressed air tank for providing pulse jetoperation, between each pulse. In a second, a large onboard compressorsystem that is used for other systems on the vehicle, for example thebrake system, may be present; an example being a 1-5 horsepower (hp)compressor capable of providing 10 cfm at 100 psi. When this is thecase, the compressor system can be used to provide compressed gas foroperating the pulse jet system. Such relatively large compressorsystems, are generally capable of providing pulsing without substantialdelay (for example more than 15 seconds) between each pulse, if desired.

Indeed, a 10 cubic ft/min compressor would be capable of providing up toone pulse every six (6) seconds. However, such an operation wouldtypically require the full capacity of the compressor. Thus, in manysystems in accord with the present disclosure in which a large on boardcompressor is provided, generally more than a six second delay betweenpulses is provided. On other hand a relatively small, for example ¼horsepower compressor, would typically require at least a full minute torecharge the tank, after a pulse.

In general terms, when a relatively small compressor is used, it may bedesirable to provide for either or both of: a selected time periodbetween pulses of a multiple pulse event; and, a monitoring system tocheck compressor tank (i.e. accumulator tank) pressure, before a pulseis initiated.

On the other hand, when a relatively large compressor system isavailable, the circumstances may allow an assumption that the system isappropriately charged for providing pulsing, at nearly any given time.In this situation, it may not be necessary to include as part of thepulse jet control logic any monitoring of the tank compressor, as partof a decision with respect to pulsing. Also, relatively short periods oftime between pulse events and/or individual pulsing may be acceptable.

Herein examples are described, for various ones of these types ofsystems. From the examples, and the general control logic discussed,general principles will be understood.

-   C. Pulse Jet Operation Logic

Various pulse jet operation logic approaches can be applied, forimplementation of pulse jet operations in accord with the principlesdescribed herein. These approaches include ones described in the variouspublications referenced herein above and incorporated by reference.However, some advantageous logic approaches have been developed. Theseare characterized herein, generally, as being progressive pulsingsystems. By the term “progressive” it is meant that the control logicmodifies some aspect of the pulsing, depending on the circumstancesencountered in the field. That is, there are not simply “pulse on” or“pulse off” circumstances, but rather there are modifications in whatoccurs when the pulsing is on and/or when the pulsing is selected tobecome on at some point.

Herein, distinctions are made between definitions of a “pulse” and a“pulse event.” A pulse is a single operation of a valve system, to causea compressed gas pulse to be directed into an interior of a filter of anair cleaner assembly in accord with the present disclosure. A “pulseevent” is a set of one or more individual pulses conducted in accordwith defined parameters.

One of the variables that relates to the pulsing control logic is theamount of pulsing in a pulse event, generally referred to herein by thedesignator “A.” The amount of pulsing (A) can be a function of: apre-selected number (Q) of individual pulses; or, providing individualpulses over a selected period of time (N), for example with a selectedinterval (M) between pulses. Variations in: (a) the pre-selected amountof pulsing (Q), or, (b) the time period (N) of pulsing and/or interval(M) between individual pulses, can be used to provide different amountsof pulsing (A) under different circumstances, i.e. in different (orprogressive) pulse events.

In general terms, whether or not pulsing activity is to be initiated ata given point, in part will typically be a controlled function of arestriction condition (R_(c)) of the air cleaner system. The restrictioncondition (R_(c)) is generally reflective of an amount of restrictionprovided to air flow through the air cleaner assembly, by a filtercartridge within the assembly. Variation in the restriction condition(R_(c)) for a given air cleaner assembly and engine system is a functionof: engine draw (i.e. RPM) and, amount of dust load on the cartridge. Ingeneral, a relative increase in either or both of engine RPM and dustload leads to an increased restriction condition (R_(c)).

In general, then, the restriction condition (R_(c)) can be monitored(assessed) either directly or indirectly. Indirect monitoring, forexample, would be by monitoring engine RPM. Direct monitoring, forexample, would be by measuring a pressure differential (AP) between: (1)a location within the air cleaner or air cleaner system downstream of afilter cartridge; and, (2) another location, for example the atmosphereor a location within the assembly but upstream of the filter cartridge.In a typical system, the Restriction Condition (R_(c)) is monitored bymeasuring a pressure differential between a location downstream of thefilter cartridge (within the air cleaner assembly or duct workdownstream of the air cleaner assembly) and a location exterior of theair cleaner, i.e. and atmospheric pressure.

Examples of progressive pulse control logic and methods of operating apulse jet air cleaner assembly in accord with progressive pulse controllogic can preferably be defined in accord with the above principles. Forexample: (1) for a pulse jet air cleaner assembly that includes acartridge positioned within a housing; (2) and, operation that generallyinvolves: directing inlet flow of air to be filtered into the housing;and, filtering the air by passage through the filter cartridge in afiltering flow direction; (3) pulse jet operation generally involvesdirecting a cleaning pulse flow through the filter cartridge in adirection generally opposite the filtering flow direction. In generalterms herein, a “cleaning pulse flow”, i.e. a pulse event, can be one ormore individual pulses and will typically comprise a plurality ofpulses. (It is noted that in a system as described in which the aircleaner assembly includes an inlet flow valve arrangement such as aninlet flap valve 60 described above, as cleaning pulse flow occurs,filtering flow maybe momentarily inhibited).

In general, as an example of progressive pulse control logicprogramming, such a system can be operated with a pulse control logicsuch that the cleaning pulse flow is provided accord with a pulsecontrol logic in which:

-   -   (1) When a restriction condition (R_(c)) reaches a level of at        least W, pulsing is conducted for a selected amount A₂, when        next Rc drops to Z₂ or less, wherein Z₂ is less than W (i.e.        Z₂<W); and,    -   (2) If a restriction condition (R_(c)) of at least W is not        reached within a selected time period T, pulsing is nevertheless        conducted for a selected amount A₁; for example when R_(c) next        drops to Z₁, or less; as an example wherein A₁₁ is less than        A₂(i.e. A₁<A₂).

In other words, for a system with the control logic outlined above, arestriction condition (R_(c)) is monitored. That restriction condition(R_(c)) can be (for example) an indirect measurement (engine RPM) or adirect measurement (pressure differential, ΔP). In either case, thecontrol logic can be a program which provides that, if (when) therestriction condition (R_(c)) reaches some defined level W, pulsing willstart after W is reached, but only when next R_(c) next drops to somedefined level (Z₂) or less. Further, the system is programmed so that ifa sufficient period of time (T) passes and a restriction condition W hasnot been reached (which would trigger the pulsing event or at least thepotential for a pulsing event) the system would nevertheless startpulsing for a selected amount A₁, when next a selected RestrictionCondition (R_(c)) of Z₁ or less is reached. Here, the progression can,in part, provided by having the amounts A₁ and A₂ differ, for examplewith A₂>A₁, although alternatives are possible. In the specific definedexample, the amount A₁ is greater than A₂. This is logical since theamount A₂ would not be triggered unless restriction has been observed tohave been raised to W, indicative of greater dust flow into or throughthe cartridge as represented by either: increase in restriction providedby the cartridge, or increased engine draw.

Of course, the amount of pulsing (A₁, A₂): (a) can be pre-selected in asystem that allows for a selected amount or number (Q) of pulses; or,(b) it can be controlled by a controlled total time period (N) ofpulsing, for example with a selected time interval (M) between pulses.

As an example, the timer could be initiated when the engine starts torun, and if defined pressure limits having been reached, the cleaningcycle in accord with (2) can be initiated, for three minutes. However,this cycle would not involve pulsing until a reading at or below aspecified pressure (Z₁) is reached, for a typical system. After thepreconditioned pressure (Z₁) is reached, and the three minutes ofpulsing occurs, the control logic will then restart the timing again, sothat after an hour of operation, the pulsing in accord with (2) willagain be initiated (once the precondition (Z₁) of the low pressure isreached) unless in the intervening hour the restriction condition(R_(c)) leading to (1) described above is reached.

Typically, the system will be configured so that should the pressurerise to above the selected control limit, (Z₁ for (2) and Z₂ for (1))while the pulsing event is occurring, the pulses will stop, with thepulse event completed once the pressure (R_(c)) again drops below thedefined amount (Z₁ or Z₂).

The progressive logic can be extended to define still further pulseevents. For example, the same system defined above, could also beprogrammed so that a cleaning pulse flow is conducted in accord with apulse control logic further wherein:

-   -   (3) When (if) a Restriction Condition (R_(c)) reaches a level of        at least X, pulsing is conducted for an amount A₃ when next Rc        drops to Z₃ or less. For example, this might be conducted in        accord with programming wherein Z₃ is less than X (Z₃<X), X is        greater than W (X>W); and, A₃ is greater than A₂, (A₃>A₂),        although alternatives are possible.

Again, typically if a pulsing event in accord with (3) is initated as aresult of the restriction condition (R_(c)) having reached Z₃ or less,should the restriction condition (R_(c)) raise above Z₃ while a pulsingis occurring, the system can be programmed to stop pulsing and tocomplete the pulsing event once the restriction condition (R_(c)) ismeasured as having dropped to or below Z₃.

In general terms, a restriction condition (Rc) of X would be indicationof even greater dust load occurring, and thus a preference for greaterpulsing to provide cleaning effect and to return the air cleaner to amore desired level of operation.

It is anticipated that pulse control logic programming will be preferredto be such that in some instances, once the restriction condition(R_(c)) has been measured as reaching some defined level, for example ithas at least reached level “Y”, pulsing should be conducted withoutwaiting for the restriction condition (Rc) to drop below some definedlevel. Thus, the progressive pulse control logic could be such that insuch a situation the cleaning pulse is conducted in accord with thepulse control logic further wherein:

(4) When (if) the restriction condition (Rc) reaches a level at least Y,pulsing is conducted for an amount A₄. Typically, this would be asituation in which Y is greater than each of X and W (Y>X and Y>W).

When the control logic includes providing for a cleaning pulse if therestriction condition reaches some amount Y, without waiting for therestriction condition to drop below some level, as described in theprevious paragraph at (4), in typical instances the programming willalso include implementing follow-up pulsing in accord with conditionsappropriate for at least a selected one of A₂ and A₃, for example asdefined above at (2) and (3).

Typically when this latter occurs, the pulsing event is immediatelystarted in accord with a selected one of (2) and (3) after the pulsingA₄ is completed, and once the precondition of restriction condition(R_(c)) (Z₂ or Z₃ respectively) is met, without necessarily seeing anintervening level of X or Y respectively, met.

In general terms, then, step (4) outlined above is a progression whichleads to immediate pulsing should the restriction condition (R_(c))reach some relatively high defined level. It also provides for afollow-up step down, when the option outlined in the previous paragraphis used, since in such a situation, the relatively dusty environmentand/or cartridge will have occurred.

An example of progressive control logic system which uses each of theabove principles then can be defined a system having Tiers (levels) asfollows:

-   -   Tier 0: Pulse an amount A1 every time period T, when the        Restriction Condition (R_(c)) is no greater than Z₁ provided the        conditions of Tier 1, 2 and 3 do not implement.    -   Tier 1: If the Restriction Condition (R_(c)) reaches W, but does        not reach X, when the restriction condition (R_(c)) next drops        to Z₂ or below, pulse for an amount A₂.    -   Tier 2: If the Restriction Condition (R_(c)) reaches X, but does        not reach Y, when the Restriction Condition (R_(c)) next drops        to Z₃ or below, pulse for an amount A₃.    -   Tier 3: If the Restriction Condition (R_(c)) reaches Y; pulse        for an amount A₄, without waiting for a drop in the Restriction        Condition (R_(c)); and, then, after pulsing for an amount A₄,        implement a Tier 2 type pulse event; i.e. when the Restriction        Condition (Rc) next drops below Z₃, pulse for an amount A₃.

In each of the Tiers, when a pulse event is conditioned upon a selectedrestriction condition (R_(c)) (i.e. Z₁, Z₂, Z₃) at or below which thepressure must be reached, typically the control system will beprogrammed to pause pulsing, should, during the pulsing event, therestriction condition (R_(c)) increase above the control amount (Z₁, Z₂,Z₃), until the R_(c) next drops to or below that control amount, atwhich point the pulsing event can be continued until completed. It isalso noted that the programming can be selected so Z₁, Z₂, Z₃ are atlevels below which the restriction condition (R_(c)) must be, beforeinitiation of a pulsing event, rather than a level at or below which arestriction condition (R_(c)) must be. Herein, these alternatives aretreated as equals, when the system is a defined above because only analgebraic variable (Z₁, etc) is used for the assigned level, as opposedto a specified numerical amount.

In the example, after the pulsing A₄ in Tier 3, the Tier 2 pulsing eventis initiated without regard to whether restriction condition (R_(c))again reaches X. Since Y is typically greater than X, it will be assumedby the control system that X has been reached, and pulsing will beconducted as long as the precondition of R_(c) being below Z₃ is met.

In an example such system:

-   -   1. The Restriction Condition (R_(c)) can be a measured        differential pressure (ΔP) across the filter cartridge (i.e.        between a location downstream of the cartridge and the        atmosphere).    -   2. The amounts A₁, A₂, A₃, and A₄ can be managed with a selected        time interval (M₁, M₂, M₃, M₄) between pulses, and with a        selected time period (N₁, N₂, N₃, N₄) of each total pulse event.        (For example, in Tier 0 pulse every 20 seconds (M₁) for a time        (N₁) at 3 minutes in each hour (T).    -   3. Typically: W<X<Y    -   4. If desired, Z₁=Z₂=Z₃    -   5. Typically the time interval (M) between pulses in each of the        Tiers will not be greater than 120 sec. Usually it will not be        greater than 100 sec.        -   (a) When a large onboard compressor is available, typically            the time interval between pulses will not be greater than 70            seconds.            -   (1) The time interval between pulses in each Tier can be                the same, as an example 60 sec.            -   (2) The time interval between pulses can be varied among                the Tiers; for example: 20 seconds for Tier 0, 1 and 2;                and, 60 seconds for Tier 3.        -   (b) Typically with a large compressor it will not be            necessary to check tank pressure between pulses.

Two specific examples of such systems would be as follows:

EXAMPLE A

-   -   Tier 0: Pulse for 3 minutes every hour when ΔP (R_(c) as        measured by restriction) drops below 6.5 inches H₂O, if pressure        limits from Tier 1, 2 and 3 have not been reached.    -   Tier 1: If pressure reaches 24 inches H₂O≦ΔP<26 inches H₂O),        pulse for 6 minutes when ΔP next drops below 6.5 inches H₂O.    -   Tier 2: If pressure reaches 26 inches H₂O≦ΔP<28 inches H₂O,        pulse for 9 minutes when ΔP next drops below 6.5 inches H₂O.    -   Tier 3: If pressure is ΔP≧28 inches H₂O, pulse for 21 minutes        regardless of ΔP; also at the end of the 21 minutes engage a        Tier 2 cleaning cycle.    -   Pulse Interval: Every 20 seconds—Tier 0, 1 and 2; Every 60        seconds—Tier 3

EXAMPLE B

-   -   Tier 0: Pulse for 3 minutes out of every hour when ΔP drops        below 5 inches H₂O, if pressure limits from Tier 1, 2 and 3 have        not been reached.    -   Tier 1: If pressure reaches 16 inches H₂O≦ΔP<19 inches H₂O,        pulse for 6 minutes when ΔP next drops below 5 inches H₂O.    -   Tier 2: If pressure reaches 19 inches H₂O≦ΔP<22 inches H₂O,        pulse for 9 minutes when next ΔP drops below 5 inches of H₂O.    -   Tier 3: If pressure reaches ΔP≧22 inches H₂O, pulse for 21        minutes regardless of ΔP; and, at the end of the 21 minutes        engage a Tier 2 cleaning cycle.    -   Pulse Interval: Every 60 seconds in each Tier.

It is noted that the systems described previously in this section(Examples A and B) were described without requiring a specific step ofmeasuring or monitoring compressed gas tank (i.e. accumulator tank)pressure. Of course a step of measuring tank pressure could be used aany of the protocols defined, with pulsing not initiated unless anduntil a minimum tank pressure is measured. However, if the vehicle orequipment has a sufficiently large compressor system, the control logiccan be programmed to implement independently of measurements of tankpressure, since it can be assumed that an adequate tank pressure toprovide pulses is always present, if the time interval between pulses isadjusted. Indeed, in some instances, the pulse control logic approachesof examples A and B can be implemented in a system in which the aircleaner assembly does not include an accumulator tank or gas compressiontank but rather in which the tank is positioned remotely, associatedwith the relatively large compressor and other compressed gas operatingsystems.

An example general approach for progressive pulse control logic in asituation, in which the accumulated tank pressure should be checkedbefore pulsing, would be as follows:

-   -   Tier 0: Pulse an amount of A₁ every hour when ΔP drops below Z₁,        inches H₂O, if pressure limits from Tier 1, 2 and 3 have not        been reached and accumulator tank pressure is above 100 PSI.    -   Tier 1: If pressure reaches W≦ΔP<X pulse an amount A₂ when ΔP        next drops below Z₂ and accumulator tank pressure is above 100        PSI.    -   Tier 2: If pressure reaches X≦ΔP<Y, pulse for an amount A₃ when        ΔP next drops below Z₃ and accumulator tank pressure is above        100 PSI.

Tier 3: If pressure is ΔP≧Y, pulse an amount A₄ regardless of ΔP, ifaccumulator tank pressure is above 100 PSI; and, at the end of the A₄pulsing engage a Tier 2 cleaning cycle.

In an example such system,

W<X<Y; and, A₁<A₂<A₃<A₄

In applications where a small compressor is used, the pulse interval (M)is normally determined by the time it takes the compressor to charge theair accumulator to the desired pulse pressure (typically 100 psi). Whenthe air accumulator reaches a target pressure (typically 100 psi) apressure switch (or other type of sensor such as a pressure transducer)on the air tank signals the control circuit to actuate a cleaning pulse.The actual time it takes to recharge the air tank is affected by suchfactors as the output capacity of the compressor used and the volume ofthe air tank. The types of compressors of low power typically used withsystems of the type characterized herein would typically take between 30and 90 sec to recharge the air tank. The condition of the compressor canalso influence air tank recharge time (as the compressor wears, rechargetime may become longer). A pressure switch is used to actuate a pulse inthis manner to ensure that pulses always occur at the desired pressureand that cleaning pulses occur at the shortest interval possible (pulseoccurs as soon as air tank reaches target pressure).

A specific example would be as follows:

EXAMPLE C

-   -   Tier 0: Pulse 3 times within each hour, when ΔP drops below 5        inches H₂O, if pressure limits from Tier 1, 2 and 3 have not        been reached and accumulator tank pressure is above 100 psi.    -   Tier 1: If pressure reaches 16 inches H₂O≦ΔP<19 inches H₂O,        pulse for 6 minutes, when ΔP next drops below 5 inches H₂O and        accumulator tank pressure is above 100 psi.    -   Tier 2: If pressure reaches 19 inches H₂O≦Δ22 inches H₂O, pulse        for 9 minutes when ΔP nest drops below 5 inches H₂O and        accumulator tank pressure is above 100 PSI.    -   Tier 3: If pressure reaches ΔP≧22 inches H₂O, pulse for 21        minutes regardless of ΔP, if accumulator tank pressure is above        100 psi; and, at the end of the 21 minutes engage a Tier 2        cleaning cycle.    -   Pulse interval for each Tier: 60 seconds

-   B. Other Features

In WO 2007/149388 and U.S. 2009/0308034, some selected usable materialsfor valve arrangements are described. Analogous materials can be usedfor the valve arrangements described herein.

A variety of types of equipment can be fitted with an air cleanerassembly according to the present disclosure. A typical use would be ona military vehicle that is expected to traverse a wide variety ofterrains (for example, including with water fording), and which isexpected to be used under circumstances in which it is undesirable foroccluded air cleaners to inhibit performance for any significant time.

The principles described herein can be used with a variety of equipmentand a variety of rated air flows. Typical sizes will be with air cleanerdiameter of 10 inches to 17 inches (254-432 mm), and rated air flows of400 cfm to 1400 cfm (11.3-39.6 cu. meters/min), although alternativesare possible.

VI. Some General Comments

According to the present disclosure, features, assemblies, andtechniques of operation, for an air cleaner assembly are provided. In anaspect of the present disclosure, an air cleaner assembly is providedwhich comprises an air cleaner housing having: an air flow inlet; an airflow outlet; and, an interior. The interior is generally sized andconfigured to operably receive therein a serviceable filter cartridge.The typical serviceable filter cartridge would be removable from the aircleaner housing, and would comprise a media pack surrounding the openfilter interior. A typical media pack would comprise pleated media,comprising alternating inner and outer pleat tips, positioned inextension between first and second, opposite, end caps.

The housing includes an outer sidewall which surrounds a centrallongitudinal axis of the air cleaner housing. Selected featuresdescribed herein can be applied when the air cleaner housing is orientedwith the central axis extending generally horizontally; and, selectedfeatures described herein can be applied when the air cleaner housing isoriented with the central axis extending generally vertically.

Typically, the housing has an outer sidewall which extends around thecentral longitudinal axis, and is tubular in configuration. The outersidewall in a typical application will have (define) a generallycircular cross-section.

The housing includes a dust ejection port arrangement therein. The dustejection port arrangement includes a dust egress aperture arrangementin, i.e. through, the outer sidewall. The dust egress aperturearrangement can comprise a single aperture or plurality of apertures.

A typical assembly includes a pulse jet distribution arrangement. Thereference in this context to a “pulse jet distribution arrangement” ismerely meant to refer to a housing which has adequate features to allowfor a pulse jet flow to be directed into an internally received filtercartridge, in a direction opposite normal filtering flow. When thecartridge comprises media surrounding an open filter interior, this willtypically comprise features adequate to direct pulse jet flow into theinterior of the cartridge and then through the media of the cartridge.The pulse jet distribution arrangement can, for example, comprise apulse jet flow tube, oriented to direct the flow into the cartridge. Itcan include additional features such as a distributor end or nozzle, andindeed the air cleaner assembly can include an accumulator tank andvarious pulse jet valve and pulse jet valve control assemblies, ifdesired.

In a certain example arrangements described herein, the dust ejectionport arrangement comprises a dust egress aperture arrangement on theouter sidewall that extends over a radial arc of at least 20°, typicallyat least 30°, often at least 45°, usually no more than 120°, typicallyno more than 110° and often within the range of 45°-90°, inclusive. Theterm “radial arc” in reference to the dust ejection port arrangement ismeant to refer to an arcuate distance along the housing outer sidewall,measured as an arc around the central longitudinal axis, betweenradially most extreme edges or portion of the dust egress aperturearrangement. When the dust egress aperture arrangement comprises asingle aperture, this would be the radial arc between most opposite endsof the arc. When the dust egress aperture arrangement comprises morethan one aperture, it may analogously be a distance between furthestradially remote edge regions, of furthest radially remote apertures inthe dust egress aperture arrangement.

In a typical system, a dust receiver is a housing positioned exteriorlyof the air cleaner housing, orientated to receive dust (from the dustegress aperture arrangement) directed into on interior of the dustreceiver housing.

Typically, the air cleaner assembly defines (provides) a dust rotationdirection. This is generally meant to refer to a direction around thecartridge (between the filter cartridge and the sidewall) into which airand dust directed into the housing is generally directed to flow orspiral. It provides for a cyclonic cleaning effect as a pre-separationof dust within the assembly. The term “dust rotation direction”, then,is meant to refer to this spiraling direction. Generally, two directionsare available: clockwise and counter-clockwise, given a specificorientation of observation. The spiraling or dust rotation directionwill typically be defined by various features in the housing including,as possibilities: a direction of inlet flow into the housing; avalve/director arrangement used within the housing; and/or a vanearrangement positioned in the housing and/or positioned on the filtercartridge. Examples of these are described.

In an example described herein, the housing includes a radially inwardlydirected scoop (or deflector) edge at an edge of the dust egressaperture arrangement most radially downstream with respect to the dustrotation direction. This would be, then, a scoop or collector edge whichhelps collect dust as it passes over or across the dust egress aperturearrangement in the housing sidewall, when moving in the dust rotationdirection. A typical such scoop or collector comprises an inwardlydeflected portion of the housing sidewall, or an extra member secured toan inside of the housing sidewall. In an example system described, thedust receiver has a bottom wall section that engages the housingsidewall at a location lower than a lowermost portion of the dust egressarrangement, typically at least 0.25 inch (6.4 mm) lower, usually atleast 0.5 inch (12.7 mm) lower.

Selected examples are described herein, in which the dust receiverincludes at least a first substantially tangential wall section. Atangential wall section is a wall of the dust receiver that intersects asidewall of a housing with extension in a direction generallytangentially to a circle drawn around the central axis of the housingand generally corresponding to the housing sidewall. By “generally” or“substantially” tangentially or similar terms in this context, referenceis meant to a direction of extension of a wall that is in a plane nomore than +/−10° from tangential with respect to the defined circle.Typically, the first tangential sidewall section is one of two opposite,substantially parallel wall sections. In this instance, by the term“substantially parallel” is meant that they are either parallel orextend in planes at +/−10°, inclusive to of one another.

The air cleaner housing can be configured for use with a central axisthereof extending generally horizontally. When this is the case, in atleast some instances, the substantially tangential first wall section,and the opposite wall section, will typically comprise top and bottom(or bottom or top) wall sections of the dust receiver. However there isno specific requirement in such instances that the tangential wallsection of the dust receiver extend generally horizontally, and thuscomprise top and bottom wall sections of a dust receiver. Also, which istop and which is bottom is a function of orientation, and either canserve each purpose.

In some instances, the air cleaner housing is configured for use with acentral axis thereof extending generally vertically. When such is thecase, in an example assembly described herein, the first substantiallytangential wall section and second, opposite, wall section willtypically comprise sidewall sections of the dust receiver, whichsidewall sections generally extend between top and bottom sections ofthe dust receiver. Alternatives are possible.

In a typical assembly according to the present disclosure, a filtercartridge is positioned in the air cleaner housing. The filter cartridgewill typically comprise media positioned around an open filter interior.The media may define a generally cylindrical outer perimeter definition,although alternatives are possible.

The pulse jet arrangement typically includes a pulse jet tube orientedto direct a cleaning pulse jet into the open filter interior.

In an example assembly described herein, a guide rack support isprovided in the housing. The guide rack support is a support on whichthe cartridge rests, as it is installed. An example guide rack isdescribed, which comprises a loop positioned to be received in thecartridge open filter interior and directed toward an end of thecartridge remote from the pulse jet tube. The support is described asanchored to structural support within the housing. A downwardly directedend to the loop facilities cartridge installation. The guide racksupport provides a function of helping the service provider, when thecartridge is long and relatively heavy, maneuver the cartridge into aproper position during installation and removal.

As described herein above, in some instances, the air cleaner assemblyincludes a compressed gas storage tank (i.e. accumulator tank) securedto the air cleaner housing. In the example depicted, the compressed gasstorage tank is positioned in an end of the housing, surrounded by, orat least partially surrounded by, the housing sidewall. It is notedhowever, the selected features described herein can be applied whenthere is no accumulator tank secured to the air cleaner assembly.

In an example arrangement described herein, the filter cartridgecomprises media positioned in extension between first and second endcaps; the first end cap being an open end cap with a central aperturetherethrough. In an example described, an axial seal ring is positionedon the first end cap at a location directed away from the media and thesecond end cap, in a position surrounding (and in the example describedspaced from) the central aperture of the first end cap. The axial sealring is configured and positioned to be removably sealed (axially)against a portion of the housing. In an example depicted, the portion ofthe housing against which the sealing occurs, is a portion of thecompressed gas storage tank (i.e. accumulator tank). It is noted that inan example described the second end cap is generally closed, except foran aperture therethrough that receives a mounting post during mountingthe cartridge, and which is sealed closed by appropriate means when thecartridge is mounted. An example of such sealing that is described anddepicted is a wing nut with a washer arrangement.

In certain example systems described, and although alternatives arepossible, the dust egress aperture arrangement is oriented spaced,radially, upwardly from a lowermost portion of the housing sidewall, inuse, by a radial arc of at least 30°. By this it is meant that the dustegress aperture arrangement has a lowermost portion thereof, when thecentral axis is oriented substantially horizontally, positioned spacedradially around the central axis at least 30° from a lowermost portionof the housing. Typically the spacing is at least 45° from the lowermostportion of the housing, and usually it is at least 75°. Indeed, in someapplications it would be spaced at least 90° from a lowermost portion ofthe housing, leaving the dust egress aperture in the uppermost portion,i.e. the upper half, of the housing.

When the dust egress aperture arrangement comprises a plurality ofapertures, herein when reference is made to the radial positioning, itis meant to refer to the radially lowermost portion of a lowermostextending aperture thereof.

In the example assembly depicted, the air cleaner assembly includes aninlet valve/director arrangement comprising a valve member oriented tobias between a first open position and the second closed position. Whenin the first open position, the inlet valve/director arrangement allowsinlet flow through the air flow inlet into the housing, and generallyhelps direct that flow into the cyclonic pattern. When in the secondposition, the inlet valve arrangement is positioned to inhibit a pulseflow out the air flow inlet, typically by being biased to close the airflow inlet.

In an example depicted, the inlet valve arrangement comprises a valvemember mounted inside the housing and positioned for pivoting of thevalve member between the first position and the second position. Anexample member is depicted, which has a side hingedly connected to aninterior of the housing to provide for this movement. The housing mayinclude a support arrangement to help maintain the inlet valvearrangement in a desired orientation.

The dust receiver can be included with a dust ejector valve arrangementpositioned over the dust exit aperture; the dust ejector valvearrangement having first and second orientations. The dust ejector valvearrangement, when in the first orientation, closes the dust exitaperture in the dust receiver; and, when in the second orientation opensthe dust exit aperture to dust passage therethrough. The dust ejectorvalve arrangement can include a valve member hingedly mounted on thedust receiver housing.

Typically, the egress aperture arrangement has a total open area of atleast 4 sq. in (25.8 sq. cm), typically at least 6 sq. in. (38.7 sq. cm)and often within the range of 6-14 sq. in. (38.7-90.3 sq. cm), althoughalternatives are possible. (An example would be an aperture area withinthe range of 6-10 sq. inches (38.7-64.5 sq. cm), inclusive, with ahousing having a diameter of 12 inches (30.5 cm)).

Typically, the exit port arrangement in the dust receiver has an overallopen area of at least 3 sq. in. (19.4 sq. cm) typically at least 4 sq.in. (25.8 sq. cm) and often within the range of 4-8 sq. (25.8-51.6 sq.cm) in., although alternatives are possible.

Also according to the present disclosure, methods of operating a pulsejet air cleaner assembly, including cleaning a filter cartridgepositioned within a housing thereof is provided. In general terms, themethod includes steps of:

(a) directing inlet flow of air to be filtered into a housing of the aircleaner assembly in a cyclonic (spiraling or dust rotation) patternaround a filter cartridge positioned therein;

(b) filtering the air by passage of the air through the cartridge in adirection from out-to-in and into an open filter interior;

(c) at a selected time (or condition) directing the pulse jet of airinto the open filter interior and through the cartridge from in-to-out;and,

(d) directing dust in an interior of the housing through a dust egressarrangement as described and/or into a dust receiver as described.

Directing dust through the dust egress arrangement can be conducted, inpart, while the initial entry of air to be filtered is directed into thehousing. This is done by causing a portion of the dust to be directedcyclonically around the cartridge, and to be directed through the egressarrangement, for example by an outlet scoop or flange positionedadjacent the egress. This can help dust to pass through the egressarrangement and to settle into a dust receiver positioned exteriorly ofthe housing. Dust is also directed into the dust receiver, when thepulse jet operation occurs, which also serves to force dust received inthe receiver outwardly through an exit port arrangement therein. -pAlso, herein, some general progressive pulse control logic ormethodologies are described. These can be implemented with a pulse jetair cleaner assembly as generally described above, or in alternate pulsejet air cleaner assemblies. In general terms, a cleaning pulse flowthrough the filter cartridge is directed in a direction generallyopposite the filtering flow direction, for example with the step ofdirecting clean pulse flow being conducted in accord with pulse controllogic in which:

-   -   (a) when a Restriction Condition (R_(c)) reaches a level of at        least W, pulsing is conducted for a selected amount A₂, when        next R_(c) drops to Z₂ or less, for example wherein Z₂ is less        than W; and,    -   (b) when a Restriction Condition (R_(c)) of at least W is not        reached in a selected time period T, pulsing is conducted for a        selected amount A₁ when next R_(c) drops to Z₁ or less,        typically wherein Z₁<W. In an example, A₁ is less than A₂.

The Restriction Condition (R_(c)) can be monitored by monitoring engineRPM and/or monitoring pressure restriction provided by the filtercartridge. Typically, each of the pulsing amounts A₁ and A₂ willcomprise a multiple cleaning pulse event. They can be defined bypreselected number of pulses or they can be defined by providing aselected pulse interval (M) between pulses, and providing a pulsingevent extending over a selected period of time (N).

In an example methodology described, Z₁=Z₂.

Multiple progressive Tiers are described in example pulse control logicapproaches herein above. For example, a system generally ascharacterized above could be implemented with a logic further wherein:when (if) the Restriction Condition (R_(c)) reaches a level of at leastX, pulsing is conducted for an amount A₃, when Rc next drops to Z₃ orless. In an example: Z₃<X; X>W; Z₃<W; and, A₃ <A₂.

In some instances it may be desirable that once a restriction hasreached a sufficiently high amount, pulsing occurs without waiting for adrop in Restriction Condition (R_(c)). For example a system previouslycharacterized can be implemented wherein the pulse control logic furtherincludes providing for that: when (if) the Restriction Condition (R_(c))reaches a level of at least Y, pulsing is conducted for an amount A₄,wherein Y>X.

In typical example systems involving pulsing for amount A₄ as described,control logic would also include providing that after the pulsing amountA₄ occurred, pulsing in accord with the previously defined progressivelevel would be conducted, for example, pulse an amount A₃ when nextR_(c) drops to Z₃ or less.

There is no specific requirement that the Restriction Condition (R_(c))amounts Z₁, Z₂, Z₃ differ from one another.

Pulsing as indicated above will often be defined with respect to thetime period over which a pulse event occurs, referenced herein asdesignator “N” and the time interval between pulses within a pulseevent, refereed to herein generally as time interval M. There is nospecific requirement that the time interval M between pulses be the samefor any of the Tiers or stages of pulsing in a multiple Tier stagesystem. There is also no requirement that the total time period of thepulse event be the same for each of the Tiers or the stages in a pulsecontrol logic system.

A variety of alternatives are described.

Typically, the selected time interval between pulses will not be greaterthan 150 seconds, typically not greater than 120 seconds and often notgreater than 100 seconds. Indeed, some examples are described in whichit is not more than 90 seconds. Also typically the selected timeinterval between pulses will be at least 15 seconds usually at least 20seconds. A specific choice of time interval may turn on the size of thecompressor in the system.

It is noted that in some instances it may be necessary and appropriateto measure accumulator tank pressure before a pulsing event isinitiated, especially when a relatively low power compressor is used.Herein, accumulator tank pressure is sometimes referenced as “ATP.”

In another general characterization of techniques according to thepresent disclosure, a method of operating a pulse jet air cleanerassembly including a cartridge positioned within a housing thereof isprovided. The method generally includes a step of selectively directingcleaning pulse flow through the filter cartridge and in a directiongenerally opposite to a filtering flow direction; the step of directingcleaning pulse flow being generally in accord with a pulse control logicincluding at least three (3) pulse event initiation and protocol typeincluding:

-   -   (1) A base type wherein pulsing is instantiated for a selected        A₁ if a restriction condition (R_(c)) does not reach a defined        level W, within a selected time period T;    -   (2) At least one intermediate type, wherein pulsing is initiated        for a selected amount A₂ after the restriction condition (R_(c))        is observed to reach the defined level W, but only after the        restriction condition (R_(c)) next reduces to no more than a        selected level, which is typically less than W; and,    -   (3) A priority type, wherein pulsing is initiated for a selected        amount A₄ when the restriction condition (R_(c)) is observed to        reach a level Y, without waiting for a reduced restriction        condition (R_(c)) relative to Y, to next occur; wherein Y is        greater than W.

Of course the at least one intermediate type can include more than onelevel. For example, the at least one intermediate type pulse eventprotocol can be one having:

-   -   (a) a first level, wherein pulsing is initiated for a selected        amount A₂ after: the restriction condition (R_(c)) is observed        to reach a level W but not a level X, wherein X is greater than        W, but only after the restriction condition (R_(c)) next reduces        to no more than a selected level which is less than W; and,    -   (b) A second level wherein pulsing is initiated for a selected        amount A₃ after: the restriction condition (R_(c)) is observed        to reach a level X but not a level Y, but only after the        restriction condition (R_(c)) next reduces to no more than a        selected level which is less than W.

Typically, the restriction condition (R_(c)) corresponding to W is atleast 14 inches (356 mm) of H₂O. Typically, the restriction condition(R_(c)) Y is at least 3 inches (76.2 mm) of H₂O) greater than therestriction condition (R_(c)) W. Typically, the restriction condition(R_(c)) corresponding to X: is at least one inch (25.4 mm) of H₂Ogreater than the restriction condition (R_(c)) corresponding to W; and,at least one inch (25.4 mm) of H₂O less than the restriction condition(R_(c)) corresponding to Y.

Typically, the restriction condition (R_(c)) at or below which therestriction condition (R_(c)) must go, in the intermediate protocoltype, for initiating a pulsing event after having reached a level W isat least 8 inches (203 mm) of H₂O lower than W. Typically that level isat least 10 inches (254 mm) of H₂O lower than W. Often the level belowwhich the restriction condition (R_(c)) must go, for the base type ofthe intermediate type pulsing event to be initiated, is no more greaterthan 7.5 inches (191 mm) of H₂O and typically no greater than 7 inches(178 mm) of H₂O. In some instances it is no greater than 5.5 inches (14cm) of H₂O.

In a typical process, the amount A₁ is less than the amount A₂. Indeed,typically A₂ is at least 1.5 times A₁. Also, typically the amount A₄ isgreater than A₁, usually A₄ is at least two times the amount A₁.

Of course in accord with the present disclosure an air cleaner assemblyis provided which includes an air cleaner housing having an air flowinlet; an air flow outlet and an interior and a dust ejection portarrangement. A filter cartridge is positioned within the housinginterior and the pulse jet arrangement is provided configured to directthe cleaning pulse flow through the filter cartridge. The pulse jetarrangement includes a logic protocol program to provide pulsing inaccord with the descriptions herein above.

There is no requirement that an assembly or method include all of thefeatures and techniques described herein, in order to obtain somebenefit according to the present disclosure.

What is claimed:
 1. A method of operating a pulse jet air cleanerassembly for filtering intake air to an internal combustion engine andincluding a cartridge positioned within a housing thereof; the methodincluding steps of: (a) directing inlet flow of air to be filtered intoa housing of the air cleaner assembly; (b) filtering the air by passagethrough the filter cartridge in a filtering flow direction; and, (c)selectively directing cleaning pulse flow through the filter cartridgein a direction generally opposite the filtering flow direction; the stepof directing cleaning pulse flow being in accord with a pulse controllogic in which: (i) when a restriction condition R_(c) reaches a levelof at least W, pulsing is conducted for a selected amount A₂, when nextR_(c) drops to Z₂ or less, wherein Z₂<W; (ii) when a restrictioncondition R_(c) of at least W is not reached within a selected timeperiod T, pulsing is conducted for a selected amount A₁, when next R_(c)drops to Z₁ or less; and; (iii) if the restriction condition R_(c)reaches a level of at least X, pulsing is conducted for an amount A₃,when next R_(c) drops to Z₃ or less, wherein: Z₃<X; X>W; and, Z₃<W.
 2. Amethod according to claim 1 wherein: (a) the pulsing amounts A₁, A₂ andA₃ each comprise multiple cleaning pulses.
 3. A method according toclaim 2 wherein: (a) A₁<A₂.
 4. A method according to claim 3 wherein:(a) A₃>A₂.
 5. A method according to claim 1 wherein: (a) Z₁=Z₂.
 6. Amethod according to claim 1 wherein: (a) the selected amount A₁comprises pulsing for a selected pulse event time period N₁.
 7. A methodaccording to claim 6 wherein: (a) the selected amount A₂ comprisespulsing for a selected pulse event time period N₂, wherein N₂>N₁.
 8. Amethod according to claim 7 wherein: (a) the selected amount A₃comprises pulsing for a selected pulse event time period N₃, whereinN₁<N₃.
 9. A method according to claim 1 wherein: (a) the selected amountA₁ comprises pulsing with a selected time interval M₁ between pulses;(b) the selected amount A₂ comprises pulsing with a selected timeinterval M₂ between pulses; and, (c) the selected amount A₃ comprisespulsing with a selected time interval M₃ between pulses.
 10. A methodaccording to claim 9 wherein: (a) the selected time period M₁ is nogreater than 120 sec.
 11. A method according to claim 931 wherein: (a)the selected time period M₁ is at least 15 sec.
 12. A method accordingto claim 1 wherein: (a) the restriction condition R_(c) is evaluated bymonitoring engine RPM.
 13. A method according to claim 1 wherein: (a)the method includes a step of checking an accumulator tank pressurebefore pulsing; and, (b) the pulsing is only conducted if theaccumulator tank pressure (ATP) is above a selected amount.
 14. A methodaccording to claim 1 wherein: (a) the cleaning pulse flow is conductedin accord with a pulse control logic further wherein: (i) when therestriction condition R_(c) reaches a level of at least Y, pulsing isconducted for an amount A₄, wherein Y>X.
 15. A method according to claim14 wherein: (a) after pulsing is conducted for an amount A₄, pulsing isconducted for an amount A₃, when next R_(c) drops to Z₃ or less.
 16. Amethod of operating a pulse jet air cleaner assembly for filteringintake air to an internal combustion engine and including a cartridgepositioned within a housing thereof; the method including steps of: (a)selectively directing cleaning pulse flow through the filter cartridgein a direction generally opposite to a filtering flow direction; thestep of directing cleaning pulse flow being in accord with a pulsecontrol logic including at least three (3) pulse event initiation andprotocol types, including: (i) a base type wherein pulsing is initiatedfor a selected amount A₁, if a restriction condition (R_(c)) does notreach a defined level W, within a selected time period T; (ii) at leastone intermediate type, wherein pulsing is initiated for a selectedamount A₂ after the restriction condition (R_(c)) is observed to reachthe defined level W, but only after the restriction condition (R_(c))next reduces to no more than a selected level, which is less than W;and, (iii) a priority type, wherein pulsing is initiated for a selectedamount A₄ when the restriction condition (R_(c)) is observed to reach alevel Y, without waiting for a reduced restriction condition (R_(c))relative to Y, to next occur; wherein Y>W.
 17. A method according toclaim 16 wherein: (a) the at least one intermediate pulse event andprotocol is one comprising: (a) a first level, wherein pulsing isinitiated for a selected amount A₂ after: the restriction condition(R_(c)) is observed to reach a level W but not a level X, wherein X>W,but only after the restriction condition (R_(c)) next reduces to no morethan a selected level which is less than W; and, (ii) a second levelwherein pulsing is initiated for a selected amount A₃ after: therestriction condition (R_(c)) is observed to reach a level X but not alevel Y, but only after the restriction condition (R_(c)) next reducesto no more than a selected level which is less than W.
 18. An aircleaner assembly comprising: (a) an air cleaner housing have an air flowinlet, an air flow outlet, and an interior; and, a dust ejection portarrangement; (b) a filter cartridge positioned in the housing interior;and, (c) a pulse jet arrangement configured to direct a cleaning pulseflow through the filter cartridge; the pulse jet arrangement includinglogic protocol programming to provide pulsing in accord with thefollowing; (i) when a restriction condition R_(c) reaches a level of atleast W, pulsing is conducted for a selected amount A₂, when next R_(c)drops to Z₂ or less, wherein Z₂<W; (ii) when a restriction conditionR_(c) of at least W is not reached within a selected time period T,pulsing is conducted for a selected amount A₁ when next R_(c) drops toZ₁ or less; and, (iii) if the restriction condition R_(c) reaches alevel of at least X, pulsing is conducted for an amount A₃, when nextR_(c) drops to Z₃ or less, wherein: Z₃<X; X>W; and, Z₃<W.
 19. An aircleaner assembly according to claim 18 wherein: (a) the housing includesa dust ejection port arrangement; (i) the dust ejection port arrangementincluding a dust egress aperture arrangement in the outer sidewalloriented spaced radially from a lowermost portion of the housingsidewall, in use, by a radial arc of at least 30°;and, (b) a dustreceiver is positioned exteriorly of the housing and oriented to receivedust from the dust egress aperture arrangement.
 20. An air cleanerassembly according to claim 19, including: (a) an inlet valve/directorarrangement oriented to bias between a first, open, position and asecond, closed, position; (i) when in the first, open, position, theinlet valve/director arrangement directing inlet flow from the air flowinlet into the housing; and, (ii) when in the second, closed, position,the inlet valve/director arrangement being positioned to inhibit pulseflow out the air flow inlet.